Apparatus for clarifying liquids



A. H. ZElTZ APPARATUS FOR CLARIFYING LIQUIDS Dec, 13, 1932.

Filed Oct. 7, 192

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M m/ b A TTbR/VE V Patented Dec. 13, 1932,

PATENT OFFICE ARTHUR ZEITZ, OF KANSAS CITY, MISSOURI arruwrus ron man-me mourns Application filed. October 7, 1929. Serial No. 397,984.

to reduce the cost'of installations for preliminary treatment of city water supplies and the like, to reduce the expense of treating city water supplies and sewage, and to increase the efliciency of clarifying apparatus.

Further objects of my invention are to facilitate the cleaning of settling basins and removal of sludge. I

In accomplishing these and other objects of the invention, I have provided improved details of structure, the preferred forms of which are illustrated in the accompanying drawing, wherein:

Fig. 1 is a central vertical section through clarifying apparatus constructed .in accordance with my invention.

Fig. 2 is a plan view of the apparatus illustrating the operation of cleaning devices.

Fig. 3 is an enlarged detail section of the conical bottom of the reservoir and portions of conduits, the walls of the conduits being partly broken away to better show construction and function.

Fig. 4 is an enlarged detail section of an edge portion of the reservoir illustrating the so intake of a discharge conduit connected with the annular collecting flume.

Referring in detail to the drawing:

1 designates a tank or reservoir having preferably a conical bottom and formed, for

exam le, by laying concrete in an excavation 1n the earth, the upper edge or periphery of the reservoir being located slightly below the ground level for a. purpose presently disclosed.

A liquid inlet conduit 2 is installed in a horizontal tunnel-3 extending below the reservoir having a base elbow 4 supported by a base 5 in a foundation block 6 below the apex of the reservoir. An inlet pipe 7 extends upwardly from the elbow on the axis of the reservoir for delivering the inlet stream of liquid to the center of the reservoir for radial flow to the perimeter of the same.

A flange and flare casting 8 is mounted on the upper end of the inlet pipe and brackets 9 fixed to the flange support, a circular steel plate 10 comprising a stillin bafiie for breaking up currents created by ii ow of water over the edge of the mouth 8.

Extending circumferentially around the perimeter of the reservoir bottom is a peripheral collecting fiume including an outer wall 11 projecting substantially above the ground level and an inner wall 12 forming a weir over which water flowing radially from the intake, passes into the fiume. The mouth of the inlet may be located at anyudesired elevat-ion above or below the surface of liquid in a-reservoir,and in the illustrated ap lication of the invention is located substantially in the plane of the edge of the weir wall 12. The u er edges of the outer and inner walls 11 and 12 are in planes parallel with the water level.

The bottom or floor 13 of the annular e- 7 ripheral oiitake flume is sloped as indicate in Fig. 1 to provide a depressed portion toward which the liquid in the trough will gravitate and a discharge outlet conduit 14 is mounted: in the outer wall 11 for communication with the fiume at the deepest portion thereof. Adjustable weir plates 15 having overlap-' ping ends-are preferably mounted on the inner face of the weir wall 12 and preferabl have transverse slots 16 for receiving bolts 1 fixed in the weir wall, whereby the plates may be independently adjusted angularly to an exact horizontal weir level on the entire circumference of the reservoir.

Material settling from the liquid will tend to slide or slowly creep over the bottom of the reservoir toward the conical lower end thereof. A discharge conduit or drain pipe 18 comprising a sludge line has an intake end communicating with the annular trough-like gutter or recess at the apex of the reservoir adjacent the joint between the inlet pipe and the reservoir, the drain extending in the tunnel and having a valve 19 located at the bottom of a manhole 20 whereby the flow of material through the drain may be controlled. A conical baffle 21 mounted on the inlet pipe has a fiaring!f;dge spaced from the bottom of the reservoir to form an annular inlet to the drain 18, the baflie serving as a hood 109 pension, to remove covering said trough to guard the intake of the drain and promote flow of sludge from the annular space around the pipe to the intake of the drain.

The bottom of the reservoir has different slopes Corresponding to the angles of repose of suspended matter likely to be deposited thereon, and is preferably formed with a surface generated by a revolving curved l ne or series of chords of a curved line to produce a convex settling floor over which sediment will move by gravity. The lower portion 32 of the botom will receive heavy matter first deposited from the radially moving liquid, and is therefore formed steeper than the outer portion by the incl'nation of aforesaid curved line. As an example of slopes, the lower portion may have a slope of 2 to 1, and the outer portion a slope of 2% or 3 to 1, depending on the character of material to be removed.

A high pressure water line 23 extendlng in the tunnel and controlled by a va ve 24 supplies liquid under pressure to a plurality of pipes 25 having fish tail type et nozzles 26 overlying the bottom of the reservo r andadapted to discharge liquid under pressure in sheet-like jets tangent to the surface of the reservoir for cleaning deposits therefrom.

The several annular series of jets may be operated seperafey, and are controlled by valves 27 in the pipes 25. The outer series is preferably directed laterally for setting up circular currents on the reservoir floor in a clockw se direction to aid the natural vortex and move material toward the inner jets that discharge radially toward the drain at the apex of the reservoir.

'In applying the invention, the sizeand shape of the reservoir. flame and conduits are designed conformably to the type and amount of liquid to be clarified, and the character of the sediment which is to be removed by the treatment. The slope of the bottom w ll in a l cases be substantially greater than the angle of repose of the normal sludge when inundated, to cause the sludge to gravitate toward the center drain.

The invention is particularly adapted for preliminary treatment of city water supplies that carry a large amount of matter in sus v the bulk of the suspended matter before chemicals are added for coagulation. for reducing the amount of chemicals required for coagulation. It is apparent that the invention may be employed for similar preliminary treatment of sewage, and for any liqu d clar fving purposes.

Vhen employed for clarifying a city water supplv, the reservoir is preferably circular, and the inlet pipe extends upwardly on the axis of the reservoir sutiiciently to provide for desired minimum agitation of water in the reservoir at the inlet while providing for incidental action on the water when desired.

The mouth of the inlet may, for example, extend above the level of water to provide for aeration of the stream. In the illustrated structure, the mouth extends to a point at or below the level of the weir, to minimize agitation of liquid in the reservoir adjacent the inlet and assure immediate reducton in velocity of the stream.

\Vater flowing radially from the inlet in all directions equally and over equal distances to the weir will pass over the weir and be carried by the flume to the efilu'ent conduit.

Heavy suspended matter will fall close to the center of the reservoir, due to change in velocity of the water upon changing from vertical to radial flow. The bell-like battle around the inlet pipe causes the sludge drain to talre up sludge from the entire area around the pipe, and thus prevents piling u a slud e at any point spaced from the inta e of the drain.

The drain valve will be set to give the drain a capacity proportionate to the capacity of the inlet conduitand suitable for the character of water supply being treated. For example, the drain will preferably have a maxlmum capacity approximately 15 per cent of the maximum capacity of the influent conduit, and will be throttled more or less depending upon the turbidity of the water being treated. 1

The lower or inner jets may be operated while the reservoir is in service to agitate and promote dislodgement of heavy material, should the material collect on the inner area of the bottom. The jets will ordinarily be operated when the reservoir is idle for cleaning the bottom.

The weir plates may be adjusted to provide a weir edge having an exact height and lying in a true horizontal plane, for example to compensate for any slight discrepancies in construction or settling after construction.

Attention is particularly called to the fact that in using the apparatus described, heavy material is separated promptly from the water and moves by gravity directly to the sludge outlet, and is there spaced a maximum distance from the points at which the clarified water leaves the reservoir.

Heavy matter is sometimes delivered in slugs in water supply streams. The slugs in apparatus as described, consisting for example of sand unlubricated by silt and having greater angle of repose than the normal sludge, will be deposited on portions of the reservoir bottom to which the inner jets may be applied without hazard of distributing the stirred-up sludge to the efiluent water.

The inner series of jets is preferably arranged adjacent the outer edge of the steeper portion of the reservoir bottom, to act. on the heavy material.

In cleaning a reservoir, the supply will be suspended, the sludge drain opened to full extent, and the jets put into operation to dislodge material. 1

What I claim and desire to secure by Letters Patent is:

1. In clarifying apparatus including, a tank having a conical bottom, an inlet conduit including a portion extending through the apex of the bottom upwardly on the axis of the tank and having a discharge mouth adj a cent the liquid level, a flame at the edge of the tank for receiving liquid distributed radially from the inlet, a sludge drain having an intake communicating with the bottom of the tank adjacent the inlet conduit, and a conical bafile supported by said inlet conduit immediately above the intake of the drain.

2. In clarifying apparatus including, a tank having a conical bottom, an inlet conduit adapted to deliver water at the axis of the tank, and a circumferential flume for receiving liquid distributed radially from the inlet, a segmental weir comprising independently adjustable weir plates on the inner wall of the flume for producing an exact horizontal level edge for said Wall.

3. In clarifying apparatus including a tank having a slo ing bottom, an inlet conduit adapted to eliver liquid adjacent the axis of the tank, a collecting flame at the edge of the tank, and a drain outlet connected with the bottom adjacent the axis of the tank, means including a plurality of nozzles overlying the bottom and adapted to deliver jets tangentially'to the surface of the bottom for promoting movement of deposited material to the drain outlet.

4. In clarifying apparatus including a tank having a sloping bottom, an inlet con" duit adapted to deliver a stream of liquid at the axis of the tank, a collecting fiume at the edge of the tank, and a drain outlet connected with the bottom adjacent the axis of the tank, means including a plurality of radially spaced series of nozzles having axes arranged tangentially to the surface of the bottom, the outer series of nozzles being directed laterally of the bottom for delivering jets in a clockwise direction. v

5. In apparatus of the character described,

a liquid containing tank having a sloping.

floor provided with a drain outlet, and means including a nozzle located in the floor and having portions overlying the floor for delivering a jet of liquid to the tank for dislodging deposits on said floor.

6. In apparatus of the character described including a tank having a conical floor and a drain outlet at the apex of the floor, means including a plurality of nozzles located in the floor and having outlet portions directed tangentially thereof for introducing jets of liquid at high velocity tangentially to the surface of the floor beneath the surface of liquid contained by the tank.

and a drain outlet in said bottom and adjacent its lower portion, means adjacent said bottom and having outlets tangential to the surface of the bottom for delivering liquid into and beneath the surface of liquid contained by the tank to cause said contained liquid in its path to move toward said outlet and substantially parallel to said surface.

9. In combination with a tank having a conical bottom provided with a drain outlet adjacent the apex thereof, means including a fluid conduit having an annular series of nozzles having axes tangential to said bottom for delivering streams of fluid to create umiercurrents moving toward said drain outlet in liquid contained by said tank beneath the surface of said liquid.

10. In clarifying apparatus including a tank having a conical bottom, an inlet including a pipe extending vertically in the tank at the axis thereof and. having a discharge mouth on the axis of the tank, a collect-ing fiume extending aroundthe perimeter of the tank, and an eliluent conduit connected with the fiume, a still ng bafiie fixed to said pipe and spaced from the mouth thereof, and a sludge outlet including a pipe having an intake in the bottom of the tank adjacent the inlet pipe.

11. In clarifying apparatus including a tank having an inclined bottom, a sludge gutter adjacent the lower portion of said bottom, a sludge drain connected with one side of said gutter, and an inlet to said sludge gutter including a fixed inverted cone forming a battle extending over said gutter and having an edge relatively narrowly spaced from said bottom.

12. In clarifying apparatus including a tank having a conical bottom, an inlet pipe extending upwardly through the bottom and having a discharge mouth located adjacent the normal level of liquid in the tank, a sludge gutter adjacent the lower portion of said bottom, a sludge drain connected with said gutter, and a fixed inclined baille forming a hood extending over said gutter to cause the drain to take sludge from all points around the circumference of the lower edge of the bafiie spaced closest to the floor.

13. In apparatus of the character described including a tank or the like having a weir for flow of water toor from the tank, angularly adjustable weir plates on said weir and extending above its upper edge for controlling flow of water over said weir.

14. In combination with a tank including a wall having an upper edge portion over which liquid isadapted to flow, weir plates adjustably mounted on the inner face of said fol-producing an exact horizontally level overflow edge for said wall, and means for holding said plates in position on said wall. 15. In combination with a. tank including a side Wall, plates having their upper edges extending above the upper edge of said side wall to form a horizontally extending weir, and means for adjustably securing said plates to said wall, whereby the inclination of. said upper edges of the weir plates can be varied longitudinally.

1.6. In c arifying apparatus, a tank having a side wall forming an effluent \YGlI',tl plurality of weir plates extending along said wall in overlap ing relation to each other and projecting aliove said wall, means for adjustably securing said plates to said Wall, whereby said plates can be so adjusted as to have their upper edges lie in a horizontal plane, a bottom in the tank including a portion having an outer edge located vertically closely adjacent said weir and inclined downwardly away from said weir to locate the inner edge'ot said bottom portion in laterally and vertically spaced relation with the Weir, an inlet having a discharge mouth located vertically above the inner edge of said boti tom portion, and a drain having an inlet in the bottom at a point adjacent the inner edge of said bottom.

In testimony whereof I aflix my signature.

' ARTHUR H. ZEITZ.

wall and projecting beyond its upper edge 

